The invention herein relates to pipe joints and clamps therefor and more particularly is concerned with a pipe joint and clamp therefor which is intended to be emission-free.
The internal combustion engine has been singled out as one of the greatest sources of pollution today and on this account it has been examined carefully in every respect by governmental agencies for deficiencies aside from the exhaust fumes which it emits. Additionally, automobile and truck manufacturers have become more sensitive to the well-being of the passengers and drivers of the vehicles that are produced to an extent where such manufacturers themselves have scrutinized the construction and operation of their own engines for faults.
The invention herein is concerned with improvements in the exhaust systems of vehicles motivated by internal combustion engines. The normal location of an engine is in the front of the vehicle and this requires that the exhaust fumes from the engine be vented at the rear of the vehicle. Rear-engined and mid-engined vehicles have the same problems but to a lesser extent. The problem is to transport the exhaust fumes to the tailpipe without loss of emission between the engine exhaust manifold or manifolds and the tailpipe. The ordinary exhaust system has a muffler which is interposed between the tailpipe and the exhaust manifold. High powered vehicles have two exhaust systems from the respective groups of four cylinders of the common V-8 engine with a muffler and often a resonator in addition in each system.
It is obvious that an exhaust system which includes at least one muffler and pipes between the muffler and engine and between the muffler and the rear end of the vehicle can be made in a unitary assembly with the joints permanently welded together. Such an exhaust system will be emission-free between the engine and the tailpipe vent. This would clearly prevent leaking exhaust fumes from entering the passenger compartment. Such a system would be unsatisfactory from two standpoints. In the first place it would be difficult to repair and replace and in the second place it would be very expensive to replace. No exhaust system in commercially produced vehicles today is corrosion-proof. Accordingly it is expected that during the ordinary life of a vehicle the muffler and perhaps the other pipes will at some time have to be replaced.
The problems with known exhaust systems have not been satisfactorily solved, so far as is known. The joints in such systems are not emission-free and this may be due either to the construction of the joints or the construction of the pipe clamps used with such joints or both. Presently known joints comprise telescoped lengths of pipe held in such telescoped condition by means of constricting pipe clamps. Pipe clamps known apply considerable constricting force to squeeze the outer pipe against the inner pipe of the telescoped joint. These clamps literally neck the outer pipe against the inner pipe, but in doing so, the outer pipe generally corrugates and the exhaust fumes escape through the corrugations.
In any event, present joints are not reliably emission-free.
The invention herein is directed to structure which solves the above problems. The invention comprises a joint and a pipe clamp for use with the joint and the combination of both.
In the construction of pipe clamps another problem arises. Modern high speed mass production has spawned a type of worker who must be provided with tools and assembly jobs which require no exercise of judgement. Parts must go together in a fool-proof manner and be constructed to forgive bad performance by the worker. To be specific, in the case of a pipe clamp, if there are two bolts which must be taken up in order to secure the pipe clamp to a joint, it cannot be expected of such workman that he will carefully apply torque to each bolt alternately back and forth in order to constrict the clamp evenly. Thus it is absolutely essential that the pipe clamp have only one bolt to be taken up and in so doing the workman must secure the clamp for its maximum utility and efficiency.
Prior clamps which have a single bolt take-up have not been able to apply even compression around their circumferences with resulting loss of efficiency.
The invention herein solves the problems which were inherent in prior pipe clamps that used a single bolt for take-up.
Three examples of prior art conduit joints and clamps are disclosed in the following United States Patents:
Day 711,946 Houghton, et al. 2,548,216 Class 285 129 Whitcomb 3,151,373 Class 24-279
In many applications the joint and clamp of the invention have achieved an emission-free clamped joint without the use of gaskets. However in some applications where the pipes are made of a tough metal, e.g., stainless steel, which is hard to form such that the beaded ends are not substantially uniform in shape, a gasket may be employed in the joint of the present invention between the beaded ends of the pipes.